Expressions of putative neurotransmitters and neuronal growth related genes in Merkel cell-neurite complexes of the rats

Reverse transcription-polymerase chain reaction using P-32-labeled dCTP wit h specific primers for putative neurotransmitters related and neuronal grow th-related genes (GAP-43, NGF and BDNF) were used to search for evidence of such substances in the Merkel cell. Merkel cell samples were made from sin us hairs in the facial skin of rats. The relative amount of mRNA in a tissu e sample concentrated in Merkel cells was compared semiquantitatively to th at from nearby tissue without Merkel cells. mRNAs for VIP, tyrosine hydroxy lase, substance P were found in higher concentration in Merkel cells than i n control tissues, mRNA for genes encoding pro-enkephalin, GAP-43, CGRP, NG F and BDNF were detected in the Merkel cell samples at concentration statis tically equivalent to those found in the control tissues. It was concluded that the relative concentration of mRNAs for VIP, tyrosine hydroxylase and substance P is consistent with the possibility that Merkel cell acts as a p ossible transduction element in mechanical excitation of sense organs in wh ich Merkel cells are present.